Dianthus plant named ‘Floriagate’

ABSTRACT

A new cultivar of  Dianthus  plant named ‘FLORIAGATE’ is characterized inter alia by pronounced spray habit, perennial and profuse bloom, and green foliage.  Dianthus  ‘FLORIAGATE’ is suitable for use as a flowering plant in pots, containers, window boxes and the garden, but is primarily suited for the production of cut flowers.  Dianthus  ‘FLORIAGATE’ is not hardy and is grown in a glasshouse. These traits set ‘FLORIAGATE’ apart from all other existing varieties, lines, strains or sports of  Dianthus . In particular,  Dianthus  ‘FLORIAGATE’ has bright purple/violet flowers.

Latin name of the genus and species claimed: Dianthus caryophyllus.

Variety denomination: ‘FLORIAGATE’.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is associated with and claims priority from U.S. Provisional Pat. application No. 61/139,354, filed on Dec. 19, 2008, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

A new cultivar of Dianthus plant named ‘FLORIAGATE’ that is characterized inter alia by altered inflorescence in respect of tissue and/or organelles including flowers or flower parts. This trait sets ‘FLORIAGATE’ apart from all other existing varieties, lines, strains or sports of Dianthus. In particular, Dianthus ‘FLORIAGATE’ has bright purple/violet flowers.

BACKGROUND OF THE INVENTION

The flower or ornamental plant industry strives to develop new and different varieties of flowers and/or plants. An effective way to create such novel varieties is through the manipulation of flower color. Classical breeding techniques have been used with some success to produce a wide range of colors for almost all of the commercial varieties of flowers and/or plants available today. This approach has been limited, however, by the constraints of a particular species' gene pool and for this reason it is rare for a single species to have the full spectrum of colored varieties. For example, the development of novel colored varieties of plants or plant parts such as flowers, foliage and stems would offer a significant opportunity in both the cut flower and ornamental markets. In the flower or ornamental plant industry, the development of desired (including novel) colored varieties of carnation is of particular interest. This includes not only different colored flowers but also anthers and styles.

Flower color is predominantly due to three types of pigment: flavonoids, carotenoids and betalains. Of the three, the flavonoids are the most common and contribute a range of colors from yellow to red to blue. The flavonoid molecules that make the major contribution to flower color are the anthocyanins, which are glycosylated derivatives of cyanidin and its methylated derivative peonidin, delphinidin and its methylated derivatives petunidin and malvidin and pelargonidin. Anthocyanins are localized in the vacuole of the epidermal cells of petals or the vacuole of the sub epidermal cells of leaves.

The flavonoid pigments are secondary metabolites of the phenylpropanoid pathway. The biosynthetic pathway for the flavonoid pigments (flavonoid pathway) is well established, (Holton and Cornish, Plant Cell 7:1071-1083, 1995; Mol et al, Trends Plant Sci. 3:212-217, 1998; Winkel-Shirley, Plant Physiol. 126:485-493, 2001a; and Winkel-Shirley, Plant Physiol. 127:1399-1404, 2001b, Tanaka and Mason, In Plant Genetic Engineering, Singh and Jaiwal (eds) SciTech Publishing LLC., USA, 1: 361-385, 2003, Tanaka et al, Plant Cell, Tissue and Organ Culture 80: 1-24, 2005, Tanaka and Brugliera, In Flowering and Its Manipulation, Annual Plant Reviews Ainsworth (ed), Blackwell Publishing, UK, 20: 201-239, 2006). Three reactions and enzymes are involved in the conversion of phenylalanine to p-coumaroyl-CoA, one of the first key substrates in the flavonoid pathway. The enzymes are phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H) and 4-coumarate: CoA ligase (4CL). The first committed step in the pathway involves the condensation of three molecules of malonyl-CoA (provided by the action of acetyl CoA carboxylase (ACC) on acetyl CoA and CO₂) with one molecule of p-coumaroyl-CoA. This reaction is catalyzed by the enzyme chalcone synthase (CHS). The product of this reaction, 2′,4,4′,6′, tetrahydroxy-chalcone, is normally rapidly isomerized by the enzyme chalcone flavanone isomerase (CHI) to produce naringenin. Naringenin is subsequently hydroxylated at the 3 position of the central ring by flavanone 3-hydroxylase (F3H) to produce dihydrokaempferol (DHK).

The pattern of hydroxylation of the B-ring of DHK plays a key role in determining petal color. The B-ring can be hydroxylated at either the 3′, or both the 3′ and 5′ positions, to produce dihydroquercetin (DHQ) or dihydromyricetin (DHM), respectively. Two key enzymes involved in this part of the pathway are flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′, 5′-hydroxylase (F3′5′H), both members of the cytochrome P450 class of enzymes.

The production of colored anthocyanins from the dihydroflavonols (DHK, DHQ, DHM), involves dihydroflavonol-4-reductase (DFR) leading to the production of the leucoanthocyanidins. The leucoanthocyanidins are subsequently converted to the anthocyanidins, pelargonidin, cyanidin and delphinidin. These flavonoid molecules are unstable under normal physiological conditions and glycosylation at the 3-position, through the action of glycosyltransferases, stabilizes the anthocyanidin molecule thus allowing accumulation of the anthocyanins.

The substrate specificity shown by DFR can regulate the anthocyanins that a plant accumulates. Petunia and cymbidium DFRs do not reduce DHK and thus they do not accumulate pelargonidin-based pigments (Forkmann and Ruhnau, Z Naturforsch C. 42c, 1146-1148, 1987, Johnson et al, Plant Journal, 19, 81-85, 1999). Many important floricultural species including iris, delphinium, cyclamen, gentian, cymbidium are presumed not to accumulate pelargonidin due to the substrate specificity of their endogenous DFRs (Tanaka and Brugliera, 2006, supra).

In carnation, the DFR enzyme is capable of metabolizing two dihydroflavonols to leucoanthocyanidins, which are ultimately converted through to anthocyanins (pigments that are responsible for flower color). DHK is converted to leucopelargonidin, the precursor to pelargonidin-based pigments, giving rise to apricot to brick-red colored carnations. DHQ is converted to leucocyanidin, the precursor to cyanidin-based pigments, producing pink to red carnations. Carnation DFR is also capable of converting DHM to leucodelphinidin (Forkmann and Ruhnau, 1987 supra), the precursor to delphinidin-based pigments. However, naturally occurring carnation lines do not contain a F3′5′H enzyme and therefore do not synthesize DHM.

Nucleotide sequences encoding F3′5′Hs have been cloned (see International Patent Application No. PCT/AU92/00334 incorporated herein by reference and Holton et al, Nature, 366:276-279, 1993 and International Patent Application No. PCT/AU03/01111 incorporated herein by reference). These sequences were efficient in modulating 3′, 5′ hydroxylation of flavonoids in petunia (see International Patent Application No. PCT/AU92/00334 and Holton et al, 1993 supra), tobacco (see International Patent Application No. PCT/AU92/00334), carnations (see International Patent Application No. PCT/AU96/00296 incorporated herein by reference) and roses (see International Patent Application No. PCT/AU03/01111).

Carnations are one of the most extensively grown cut flowers in the world.

There are thousands of current and past cut-flower varieties of cultivated carnation. These are divided into three general groups based on plant form, flower size and flower type. The three flower types are standards, sprays and midis. Most of the carnations sold fall into two main groups, the standards and the sprays. Standard carnations are intended for cultivation under conditions in which a single large flower is required per stem. Side shoots and buds are removed (a process called disbudding) to increase the size of the terminal flower. Sprays and/or miniatures are intended for cultivation to give a large number of smaller flowers per stem. Only the central flower is removed, allowing the laterals to form a ‘fan’ of flowers.

Spray carnation varieties are popular in the floral trade, as the multiple flower buds on a single stem are well suited to various types of flower arrangements and provide bulk to bouquets used in the mass market segment of the industry.

Standard and spray cultivars dominate the carnation cut-flower industry, with approximately equal numbers sold of each type in the USA. In Japan, spray-type varieties account for 70% of carnation flowers sold by volume, whilst in Europe spray-type carnations account for approximately 50% of carnation flowers traded through out the Dutch auctions. The Dutch auction trade is a good indication of consumption across Europe.

Whilst standard and midi-type carnations have been successfully manipulated genetically to introduce new colors (Tanaka and Brugliera, 2006, supra; see International Patent Application No. PCT/AU96/00296), this has not been applied to spray carnations. There is an absence of blue color in color-assortment in carnation, only recently filled through the introduction of genetically-modified standard-type carnation varieties. However, standard-type varieties can not be used for certain purposes, such as bouquets and flower arrangements where a large number of smaller carnation flowers are needed, such as hand-held arrangements, and small table settings.

One particular spray carnation which is particularly commercially popular is the Cerise Westpearl line of carnations (Dianthus caryophyllus cv. Cerise Westpearl). The variety has excellent growing characteristics and a moderate to good resistance to fungal pathogens such as Fusarium.

SUMMARY OF THE INVENTION

The following traits represent the characteristics of the new Dianthus cultivar ‘FLORIAGATE’. These traits distinguish this cultivar from other commercial varieties. ‘FLORIAGATE’ may exhibit phenotypic differences with variations in environmental, climatic and cultural conditions, without any variance in genotype.

-   -   1. Dianthus ‘FLORIAGATE’ exhibits pronounced spray habit.     -   2. Dianthus ‘FLORIAGATE’ blooms profusely     -   3. Dianthus ‘FLORIAGATE’ exhibits bright purple/violet flowers         (RHS N80B)     -   4. Dianthus ‘FLORIAGATE’ exhibits green (RHS 138A) foliage.     -   5. At maturity, the height of the foliage mound of Dianthus         ‘FLORIAGATE’ is 100.2 cm. The mature width of Dianthus         ‘FLORIAGATE’ is 15 to 18 cm.     -   6. Dianthus ‘FLORIAGATE’ is an herbaceous perennial.     -   7. Dianthus ‘FLORIAGATE’ is suitable for use as a flowering         plant in pots, containers, window boxes and the garden, but is         primarily suited for the production of cut flowers Dianthus         ‘FLORIAGATE’ is not hardy and is grown in a glasshouse.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a photographic representation of the flower of the new variety Dianthus ‘FLORIAGATE’. Colors may appear different from the actual colors due to light reflection but are as accurate as possible by conventional photography.

The photograph illustrates the overall appearance of the Dianthus ‘FLORIAGATE’ flower showing colors as true as reasonably possible to obtain in colored reproductions of this type. Colors in the photograph may differ from the color values cited in the detailed botanical description, which accurately describe the actual colors of the new variety ‘FLORIAGATE’.

FIG. 2 is a diagrammatic representation of the binary plasmid pCGP3366. chimeric. Selected restriction endonuclease sites are marked. Abbreviations include LB =Left Border from A. tumefaciens Ti plasmid, RB =Right border region from A. tumefaciens Ti plasmid, TetR =antibiotic, tetracycline resistance gene complex.

FIG. 3 is a photographic representation of a high resolution scan of a Southern blot autoradiograph showing 10 μg of EcoRI-treated genomic DNA from the transgenic carnation line 25958 (‘FLORIAGATE’), in comparison to 10 μg of EcoRI-treated genomic DNA from the carnation lines Cerise Westpearl, Purple Spectro and the transgenic carnation lines 19907 ('FLORIAMETRINE) hybridized with the NtALS probe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a new and distinct cultivar of carnation that is grown for use as a flowering plant for pots and containers. The new cultivar is known botanically as Dianthus caryophyllus and is referred to hereinafter by the cultivar name ‘FLORIAGATE’. The new variety may be referred to herein as Dianthus caryophyllus ‘FLORIAGATE’, Dianthus ‘FLORIAGATE’, D. Caryophyllus ‘FLORIAGATE’ and ‘FLORIAGATE’.

‘FLORIAGATE’ is a complex transgenic plant comprising a functional F3′,5′H and a DFR in petals and chimeric genetic material comprising sense and antisense fragments of the carnation plants indigenous DFR sequence (ds carnDFR), which induces hairpin RNAi (hpRNAi)-mediated silencing primarily via post-transcriptional gene silencing (PTGS). The vector pCGP3366 used to transform cells contains a chimeric AmCHS 5′: BP F3′5′H#0: petD8 3′ gene in tandem with a petunia genomic DFR-A gene, a chimeric 35S 5′: dscarnDFR: 35S 3′ cassette and the 35S SuRB selectable marker gene cassette of the plasmid pWTT2132.

The new variety originated in vitro by Agrobacterium tumefaciens- mediated transformation of cells of the Cerise Westpearl carnation with the pCGP3366 vector at Florigene Pty Ltd, in Bundoora, Victoria, Australia. Cuttings of Dianthus caryophyllus cv. Cerise Westpearl were obtained from Propagation Australia, Queensland, Australia. Transgenic plants containing the chimeric AmCHS 5′: BP F3′5′H#0: petD8 3′ gene in tandem with a petunia genomic DFR-A gene and a 35S 5′ dscarnDFR: 35S 3′ cassette were successfully generated from the cells. In addition to these genes, the plants also contained genes for acetolactate synthase resistance (SuRB) transformation selection markers. The transformation and regeneration process is described in International Patent Application No. PCT/US92/02612; International Patent Application No. PCT/AU96/00296; and Lu et al, Bio/Technology 9: 864-868, 1991 the contents of each of which are incorporated by reference.

The primary focus of the carnation generation program was to produce new cultivars of carnations which exhibited a selected and desired purple/violet color in the spray background. The term ‘FLORIAGATE’ was selected because of its pronounced production of delphinidin or delphinidin-based pigments.

The new variety was selected from a group of 47 transgenic lines. ‘FLORIAGATE’ is essentially similar to the parent in the morphological aspects of the flower, but can be distinguished from the parent through out due to the accumulation of the purple delphinidin-based pigment in the petals of the flower. For example, ‘Cerise Westpearl’ has a bud color of about 191B, while ‘FLORIAGATE’ has a bud color of about 138A. Furthermore, ‘FLORIAGATE’ can be distinguished from its parent in its node color (192A compared with 192D of the parent), leaf color (138A compared with 137A of the parent), and ground color of blade and color band around the center (N8OB compared with 58B of the parent), among other characteristics. This is a new phenotype of the transgenic line.

As compared with other known dianthus cultivars, ‘FLORIAGATE’ has an average height of about 1020 mm at flowering while Purple Spectro' is about 989.4 mm high. ‘FLORIAGATE’ has an average internode length of about 70.4 mm at the fifth internode, while ‘Purple Spectro’ has an average internode length of about 82.2 mm. Furthermore, ‘FLORIAGATE’ has a bud color of about 138A, while ‘Purple Spectro’ has a bud color of about 191B.

The new variety was originally selected in vitro as a regenerated shoot from a ‘Cerise Westpearl’ carnation cell that had been transfected with Agrobacterium tumefaciens AGLO (Lazo et al, Bio/technology 9:963-967, 1991) carrying the plasmid pCGP3366 (FIG. 2).

Asexual reproduction of the new cultivar was first accomplished in 2007 in a cultivated area of Bundoora, Victoria, Australia. The method of asexual propagation used was vegetative cuttings. Since that time the characteristics of the new cultivar have been determined stable and are reproduced true to type in successive generation of asexual reproduction.

Botanical Description of the Plant

The following is a detailed description of the new cultivar ‘FLORIAGATE’. Data was collected from plants grown indoors in Bundoora, Victoria, Australia. The Royal Horticultural Society's [[Color]]Colour Charts, Third and/or Fifth edition (London, UK), 1995 and/or 2007 were used to provide a description of observed color, except where general color terms of ordinary dictionary significance are used. Growing conditions are typical to other species, sports and lines of Dianthus.

-   Botanical Classification: Dianthus caryophyllus -   Species: caryophyllus -   Common name: Carnation -   Commercial classification: Dianthus caryophyllus 25958 -   Type: Herbaceous perennial -   Use: Used as a flowering plant for pots and containers -   Parentage: ‘FLORIAGATE’ is a transgenic plant that resulted from the     transformation of D. caryophyllus cultivar Cerise Westpearl with the     transformation vector, pCGP3366.

TABLE 1 Plant Description Bloom period All year Plant habit Spray type carnation Plant height Average plant height at flowering - 1020 mm Plant width 150 to 180 mm at flowering Plant hardiness Not tested for hardiness Root system Fine fibrous root system Propagation Vegetative propagation Cultural requirements Grown hydroponically in a greenhouse. Plants fertilized via drip irrigation system Pests and diseases Susceptible to known Dianthus pest and diseases Time and Temperature 3 to 4 weeks to produce rooted cuttings, needed to produce bench heat: 18-22° C., Air temp approx. a rooted cutting 15 to 22° C. Crop time Average days to flowering: 169.5. Stem shape Cylindrical, Ave stem length 840 mm, Ave stem diameter at 5th node: 7.7 mm Stem surface Glabrous and glaucous Stem color 137B Branching Little branching from the axils of lower leaves Internode length Average length of 5th internode: 70.4 mm Node color 192A Node dimensions 6 mm diameter and 4 mm in length

TABLE 2 Foliage Type Evergreen Shape Linear Division Simple Apex Acute Base Decurrent Venation Not prominent Margins Entire Attachment Sheathing Arrangement Opposite and spiraling up stem Surfaces Glaucous Leaf dimensions 3rd leaf from flower, Ave length: 53.9 mm, Ave width: 6.6 mm Leaf color (upper 138A and lower surfaces) Fragrance Absent

TABLE 3 Flowers Inflorescence Cymose Flower type Saliform, double and symmetrical Flower dimensions Ave corolla height: 26.3 mm, (including calyx) Ave calyx height: 28.4 mm. Fragrance Absent Bud color 138A Anthocyanin Present Bud dimensions Ave bud length: 25 mm, Ave bud width: 11.5 mm Bud shape Cylindrical Petals Persistent, apopetalous, overlapping Petal number Ave number of petals: 43.3 Petal margin Crenate Petal shape Obteltoid Petal surface Glabrous Petal dimensions Ave petal length: 45.2 mm, Ave petal width: 23.4 mm Ground color of blade N80B Color of band around N80B centre Color of middle of strap 145D Color of base of strap 145D Calyx dimensions Ave calyx length: 28.4 mm, Ave calyx diameter at apex: 16 mm Calyx color 143A Anthocyanin Absent Sepals Ave number of sepals: 5.6 Fused or Unfused Unfused Sepal color 143A Anthocyanin Absent Peduncle dimensions Ave peduncle length: 36.6 mm, Ave peduncle width: 2.2 mm Peduncle color 138A Peduncle surface Glaucous Epicalyx Present Bracts 1 pair in number (2 individual bracts) Bracts dimensions 2 mm × 28 mm Bract color 138A Anthacyanin Absent Bracteoles 1 or 2 pair Dimensions 2 mm × 18 mm Anthocyanin Absent Stipules Absent Stipules dimensions N/A Stipule color N/A Anthacyanin N/A Lastiness of flowers Not tested

TABLE 4 Reproductive Organs Stamens Ave number of stamens: 16.2 Stamen dimensions Ave length of stamen: 17.3 m Stamen color N155B Anther number Ave of normal anthers: 1.9, Ave of abnormal anthers: 8 Anther attachment Dorsifixed Anther color 156D Anther dimensions Ave anther length: 1.2 mm, Ave anther width: 0.5 mm Pollen Little pollen Pistil One that divides into 2 above the ovary Pistil dimensions Average pistil length: 28.8 mm Styles Average No: 2.4, Average length: 20.3 mm Style color 155A Stigma number Single Stigma shape A single stigma Stigma color 155A Height above petals Stigma does not protrude above petals Ovary position Superior Ovary dimensions Ave ovary height: 8.5 mm, Ave ovary width: 6.1 mm Ovary shape Obovoid Ovary color Upper: 145A, Lower: 155A Seed Absent

The Dianthus ‘FLORIAGATE’ is now described by the following non-limiting Examples.

EXAMPLE 1 GENERATION OF DIANTHUS ‘FLORIAGATE’

In order to increase the levels of delphinidin-based anthocyanins and therefore increase the chance of violet/purple/blue color in the Cerise Westpearl spray carnation flowers, a construct (pCGP3366) was prepared that included the use of a F3′5′H gene and a DFR gene and incorporation of a ds carnDFR molecule.

The DFR genomic fragment (pet gen DFR) used in this application was isolated from petunia. The petunia DFR enzyme is only capable of using DHQ and DHM as a substrate, but not DHK (Holton and Cornish, 1995 supra). This ensures that most or all of the anthocyanidin produced is delphinidin.

The F3′5′H coding sequence in the chimeric gene (AmCHS 5′: BP F3′5′H #40: petD8 3) used in the new construct was from pansy.

The dscarnDFR expression cassette (CaMV35S 5′: ds carn DFR: 35S 3) used in pCGP3366 comprised of sequences from carnation (DFR coding sequences in sense and antisense orientation) and petunia (DFR intron 1).

Preparation of the transformation vector, pCGP3366

The transformation vector pCGP3366 (FIG. 2) contains the AmCHS 5′: BPF3′5′H#40: petD8 3′ expression cassette and the petunia genomic DFR-A (pet gen DFR) genes along with a CaMV35S 5′: ds carn DFR: 35S 3′ expression cassette and the 35S SuRB selectable marker gene.

Agrobacterium tumefaciens strains and transformations

The disarmed Agrobacterium tumefaciens strain used was AGLO (Lazo et al, 1991 supra).

Plasmid DNA was introduced into the Agrobacterium tumefaciens strain AGLO by adding 5 μg of plasmid DNA to 100 μL of competent AGLO cells prepared by inoculating a 50 mL LB culture (Sambrook et al, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratories, Cold Spring Harbor, NY, USA, 1989) and incubation for 16 hours with shaking at 28° C. The cells were then pelleted and resuspended in 0.5 mL of 85% (v/v) 100 mM CaCl2/15% (v/v) glycerol. The DNA-Agrobacterium mixture was frozen by incubation in liquid N2 for 2 minutes and then allowed to thaw by incubation at 37° C. for 5 minutes. The DNA/bacterial mix was then placed on ice for a further 10 minutes. The cells were then mixed with 1mL of LB (Sambrook et al, 1989 supra) media and incubated with shaking for 16 hours at 28° C. Cells of A. tumefaciens carrying the plasmid were selected on LB agar plates containing 50 μg/mL tetracycline. The confirmation of the plasmid in A. tumefaciens was done by restriction endonuclease mapping of DNA isolated from the antibiotic-resistant transformants.

Plant transformations were as described in International Patent Application No. PCT/US92/02612 or International Patent Application No. PCT/AU96/00296 or Lu et al, Bio/Technology 9: 864-868, 1991 each incorporated herein by reference.

Cuttings of Dianthus caryophyllus cv. Cerise Westpearl were obtained from Queensland, Australia.

EXAMPLE 2 DETECTION OF THE SURB CHIMERIC GENE FROM THE TRANSFORMATION VECTOR PCGP3366 IN DIANTHUS ‘FLORIAGATE’ PLANTS

In order to determine stable transformation of Dianthus caryophyllus with the T-DNA from the transformation vector pCGP3366, transgenic plants were analyzed by Southern blot. The results are shown in FIG. 3.

Preparation of genomic DNA and Southern analysis

Genomic DNA was isolated from leaf tissues as described by Dellaporta et al, Molecular Biology Reporter 1(14):19-21, 1983. The genomic DNA (10 pg) was digested for 48 hours using 120 units of the restriction endonuclease EcoRI at 37° C. DNA fragments were separated by electrophoresis through a 0.8% w/v agarose gel. The DNA was transferred to Hybond NX membrane (Amersham) as described (Sambrook et al, 1989 supra).

The following samples were analyzed:

-   -   1. HindIII-treated λDNA standard markers (size range: 23.13,         9.42, 6.56, 4.36, 2.32, 2.03 kb),     -   2. 10 μg of EcoRI-treated genomic DNA from transgenic carnation         line 25958 (FLORIAGATE),     -   3. 10 μg of EcoRI-treated genomic DNA from non-transgenic         carnation parental line,

Cerise Westpearl,

-   -   4. 10 μg of EcoRI-treated genomic DNA from non-transgenic         carnation line, Purple

Spectro 10 μg of EcoRI-treated genomic DNA from transgenic carnation line, 19907 (‘FLORIAMETRINE’)

Following electrophoresis, the gel was prepared for blotting by a 15 minute depurination step in 0.25 M HC1, two 20 minute washes in denaturing solution (1.5 M NaCl, 0.5 M NaOH) and two 20 minute washes in neutralization solution (0.5 M Tri-HC1, pH 7.5, 0.48 M HC1, 1.5 M NaCl). DNA was capillary transferred to Hybond-NX nylon membrane (Amersham Biosciences, UK) in 20 x SSC (3 M NaC1, 0.3 M Tris-Na citrate, pH 7.0).

Preparation of probes

A probe corresponding to a 770 by fragment of the ALS (acetolactate synthase) gene from Nicotiana tabacum (NtALS) was used for Southern blot analysis. The probe fragment was originally generated by PCR and subsequently sub-cloned into an amplification vector (pBluescript II, Stratagene, USA), given a reference number (pCGP 1651) and the fragment sequenced. After confirmation of the correct sequence, the DNA fragment was isolated from the source plasmid using the restriction endonuclease HinddII. The fragment was separated by 1% w/v agarose gel electrophoresis and purified using the MinElute Gel Extraction kit and protocol (Qiagen, Australia).

32P-Labeling of DNA Probes

DNA fragments (25-50 ng) were labeled with 50 μCi of [α-32P]-dCTP (PerkinElmer Life and Analytical Sciences, USA) using a Decaprime kit (Ambion, USA). Unincorporated [α-32P]-dCTP was removed by chromatography on Sephadex G-50 (Fine) columns. The labeled probe fragment was counted using a BioScan radioisotope counter (QC:4000 XER, BioScan, USA).

Hybridization and Detection

Membranes were pre-hybridized in 10 mL hybridization buffer 50% v/v deionized formamide, 1 M NaC1, 1% w/v SDS and 10% w/v dextran sulfate) at 42° C. for 1 hour. Once denatured, 10,000,000 dpm of 32P —labeled probe was added to the hybridization solution and hybridization was continued at 42° C. for a further 16 hours. Membranes were washed twice in low stringency buffer (2 x SSC, 1% w/v SDS) at 65° C. for 30 minutes. Membranes were exposed to Kodax BioMax MS X-Ray film (Kodak, USA) with an intensifying screen at −70° C. for 16 hours. The exposed films were automatically developed using a Curix 60 X-ray developer (AGFR-Gevaert Group, Belgium). 

1. A new and distinct cultivar or Dianthus plant named ‘FLORIAGATE’ as described and illustrated herein. 